Tube writing pen

ABSTRACT

Capillary writing pens of the type having a housing defining a reservoir which communicates with a capillary writing tube extending through the lower end of the housing. The reservoir is characterized by the definition of a plurality of radially spaced capillary grooves extending inwardly from the walls of the reservoir into the writing tube, so as to suspend writing ink, regardless of inversion of the pen and to enhance flow from the reservoir into the writing tube. The writing grooves may be defined in a frustum at the lower end of the reservoir and, as well, may extend longitudinally along the walls of the reservoir into the frustum.

in States Lorenz et a1.

[ TUBE WRITING PEN [75] Inventors: Ewald Lorenz, Uelzen; WilhelmSchlink, Anderten; Bruno lKiinzler, Koldingen; Klaus-Dieter Goltermann,Hannover-Kleefeld, all of Germany [73] Assignee: Koh-ll-NoorRapidograph, llnc.,

Bloomsbury, NJ.

[22] Filed: July 20, 1973 [211 App]. No.: 331,316

[30] Foreign Application Priority Data July 21, 1972 Germany 2235880 May24, 1973 Germany l 2326431 [52] US. Cl. 401/259 [51] Int. Cl 843k 11/06,B43k l/lO [58]. Field of Search 401/258-260, 401/216 [56] ReferencesCited UNITED STATES PATENTS 2,627,844 2/1953 Johnson 401/259 ll/l97012/1973 Dahle l v 401/259 Linz 40l/2l6 Primary ExaminerLawrence CharlesCapillary writing pens of the type having a housing defining a reservoirwhich communicates with a capillary writing tube extending through thelower end of the housing. The reservoir is characterized by thedefinition of a plurality of radially spaced capillary grooves extendinginwardly from the walls of the reservoir into the writing tube, so as tosuspend writing ink, regardless of inversion of the pen and to enhanceflow from the reservoir into the writing tube. The writing grooves maybe defined in a frustum at the lower end of the reservoir and, as well,may extend longitudinally along the walls of the reservoir into thefrustum.

7 Claims, 1 Drawing Figure rues WRITING PEN BACKGROUND OF THE INVENTIONThe invention relates to a capillary writing point with a cylindricalbody receiving the capillary in its front end, which cylindrical bodyhas an inside bore accommodating a falling weight with a cleaning wire,the front end of said bore has an area tapering forward in the manner ofa frustum.

In the case of conventional capillary writing points, the front area ofthe falling weight has been flattened laterally, in order not to impedethe in-flow of drawing ink from the inside bore to the writing capillaryby the falling weight resting at the front end of the inside bore.However. it turned out that in the case of such conventional capillarywriting points difficulties can occur whenever the points are heldpointing upwards for a brief period of time, so that the drawing inkflows back out of the inside bore into the reservoir for the ink. In thecase of subsequent use a breakdown in the supply flow of the drawing inkto the writing capillary can occur, since under certain circumstancesair has settled in the frustum shaped area, which prevents thesubsequent inflow of drawing ink from the inside bore to the writingcapillary.

DESCRIPTION OF THE DRAWINGS FIG. ll, is a fragmentary, vertical section,partially in perspective, showing positioning of a conventional weightand cleaning wire assembly within the lower end of an ink reservoir,modified according to present invention.

SUMMARY OF THE INVENTION It is an object of the invention of creating acapillary writing point in which such breakdowns in the inflow of thedrawing ink are assuredly prevented.

This will be achieved in the case of a capillary writing point,according to the present invention, in that at least in the frustumshaped area, radially spaced ribs are provided which are inclinedinwardly and run essentially in the direction of the longitudinal axisof the cylindrical body. The spaces between the ribs form capillarygrooves.

The capillary grooves will hold drawing ink even, if the capillarywriting point with the writing capillary tube is held pointing upwards.Upon subsequent writing use when the writing tube is pointed downwardly,a connection is re-established between the drawing ink remaining in thecapillary grooves with the drawing ink in the inside bore or reservoir,so that an undisturbed flow of drawing ink is assured.

In addition, the radially spaced ribs forming the capillary grooves havethe advantage that a flattening of the falling weight at the front endis no longer required, as long as the outside diameter of the fallingweight is smaller than the maximum inside diameter of the frustum shapedarea.

Frequently, the annular space between the falling weight and the insidebore or reservoir wall has been developed relatively small, so that thevolume of drawing ink sustained in the inside bore and prevailing at therear end of the writing capillary tube will not become too large. Such asmaller annular space will prevent, under certain circumstances, atimely flow of drawing ink to the writing capillary tube after thereturn of the India ink into the drawing ink reservoir. Also, it mayoccur that the supply flow of drawing ink to the inside bore afterinverting the capillary writing point into a position with the writingcapillary tube point upwards, will remain interrupted for some time,because an air bubble settles for example in the area between thefalling weight and the capillary writing tube. Such an air bubbleinterrupts the inflow of the drawing ink. In both such cases the Indiaink, which is held in the capillary grooves, is initially consumedwithout there being any possibility of drawing ink flowing in. In orderto prevent with certainty a breakdown in the flow of drawing ink intothe capillary in such cases, notch type capillaries may be provided inthe inside wall of the reservoir, which are connected with the capillarygrooves in the frustum area.

The notch type capillaries, also. retain a part of the drawing ink inthe reservoir wall, because of their capillary effect. Even in case ofdrawing ink flowing backwardly from the annular space between wall andweight and into the reservoir for the drawing ink, the notch typecapillaries will discharge said drawing ink into the capillary groovesupon subsequent use. Thus, even in case of a prolonged interruption ofthe inflow of draw ing ink from the reservoir to the annulus, anundisturbed operation is assured.

DESCRIPTION OF PREFERRED EMBODIMENTS The cylindrical body 1 has aninside bore or reservoir 4, in which a falling weight 2, with a cleaningwire 3, is contained. Cleaning wire 3 extends through a central bore tothe writing capillary in the front end of the cylindrical body, whichhas not been shown.

At the lower end of the inside bore 4, there is a frustum shapedtransition area starting from the shoulder 7 pointed inwardly, in whichthere are radially spaced ribs 5, which run essentially in the directionof the longitudinal axis of the inside bore. Grooves 6 have been formedbetween the ribs 5, which have a capillary effect.

In the wall of the inside bore 4-, there are notch type capillaries 8,running in an axial direction, which extend radially inwardly as at 8into a capillary groove 6. In the present embodiment, three such notchtype capillaries are provided, two of which are shown. Naturally, thenumber of notch type capillaries 8, just like that of the correspondingnotch grooves 6, can be adapted to pertinent operating conditions anddimensions and all or a few of the capillary grooves 6 can be connectedwith a notch type capillary 8.

The notch type capillaries 8, just like the capillary grooves 6, willretain drawing ink, even if the capillary writing point is held pointingupwardly, so that upon subsequent use, the drawing ink retained in thecapillary grooves between the radially spaced ribs and the ink retainedin the notch type capillaries will flow into the writing capillary tubeand an early connection to the drawing ink flowing subsequently into theinside bore will than have been established by way of the notch typecapillaries 8. As a result. a continuous influx of drawing ink into thewriting capillary tube will be assuredin any case.

We claim:

1. In a capillary writing pen of the type including an ink reservoircommunicating axially with a capillary writing tube at one end, andincluding a weight supported in the reservoir with cleaning wireextending from the weight into the capillary writing tube, theimprovement comprising:

A. a radially inwardly extending frustum having the large diameterthereof communicating with said reservoir and the small diameter thereofcommunicating with said capillary tube;

B. said frustum being inclined forwardly and inwardly towards saidwriting tube and in the direction of ink flow;

C. said frustum being defined by a plurality of spaced ribs extendingsubstantially longitudinally and inwardly angled increasingly towardssaid writing tube;

D. said ribs defining therebetween capillary grooves communicating withsaid reservoir and said writing tube with said grooves extendingradially inwardly from the periphery of said frustum to the axis of saidwriting tube; and

E. the inner ends of said capillary grooves each defining alongitudinally extending feeding aperture spaced about the periphery ofsaid writing tube.

2. A capillary writing pen as in claim 1, including at least onelongitudinally extending groove defined in the wall of said reservoirand communicating at its forward end with at least one of said radiallyspaced grooves in said frustum.

3. A capillary writing pen as in claim 2, said longitudinally spacedgroove being V-shaped notched in cross section.

4. A capillary writing pen as in claim 2, said longitudinally extendinggroove and said radially spaced groove both being similarly notched incross section, so as to define a continued notched capillary grooveextending from the sides of said reservoir, through said frustum andinto the writing tube axis.

5. A capillary writing pen as in claim 4, said frustum including aperipheral outer shoulder at the juncture with said reservoir and saidlongitudinally extending grooves and said radially spaced groovesregistering through said shoulder.

6. A capillary writing pen as in claim 1, wherein said weight defines arelatively small annulus for ink flow adjacent the inner wall of saidreservoir.

7. A capillary writing pen as in claim 1, wherein said weight outerdiameter is less than the diameter of said frustum at the juncture withsaid reservoir.

1. In a capillary writing pen of the type including an ink reservoircommunicating axially with a capillary writing tube at one end, andincluding a weight supported in the reservoir with cleaning wireextending from the weight into the capillary writing tube, theimprovement comprising: A. a radially inwardly extending frustum havingthe large diameter thereof communicAting with said reservoir and thesmall diameter thereof communicating with said capillary tube; B. saidfrustum being inclined forwardly and inwardly towards said writing tubeand in the direction of ink flow; C. said frustum being defined by aplurality of spaced ribs extending substantially longitudinally andinwardly angled increasingly towards said writing tube; D. said ribsdefining therebetween capillary grooves communicating with saidreservoir and said writing tube with said grooves extending radiallyinwardly from the periphery of said frustum to the axis of said writingtube; and E. the inner ends of said capillary grooves each defining alongitudinally extending feeding aperture spaced about the periphery ofsaid writing tube.
 2. A capillary writing pen as in claim 1, includingat least one longitudinally extending groove defined in the wall of saidreservoir and communicating at its forward end with at least one of saidradially spaced grooves in said frustum.
 3. A capillary writing pen asin claim 2, said longitudinally spaced groove being V-shaped notched incross section.
 4. A capillary writing pen as in claim 2, saidlongitudinally extending groove and said radially spaced groove bothbeing similarly notched in cross section, so as to define a continuednotched capillary groove extending from the sides of said reservoir,through said frustum and into the writing tube axis.
 5. A capillarywriting pen as in claim 4, said frustum including a peripheral outershoulder at the juncture with said reservoir and said longitudinallyextending grooves and said radially spaced grooves registering throughsaid shoulder.
 6. A capillary writing pen as in claim 1, wherein saidweight defines a relatively small annulus for ink flow adjacent theinner wall of said reservoir.
 7. A capillary writing pen as in claim 1,wherein said weight outer diameter is less than the diameter of saidfrustum at the juncture with said reservoir.